Rock Cairns (U.S. National Park Service)

Rangers, walking groups, urge public to stop making rock towers on hiking trails - ABC News

Yosemite says rock cairns are bad — and you should knock them down - Los Angeles Times

Don't Move Rocks! Friends of the Smokies

See a Rock Cairn? Push It Over, Yosemite National Park Says

Should You Knock Over Cairns or Leave Them? Even the National Park Service Can't Agree. - Backpacker

The secret life of rock cairns - Wilderness Magazine

Zion National Park - Rock stacking in national parks may seem harmless, or even fun to make, but we invite you to reconsider the problem they pose from a broader perspective. On

Why You Shouldn't Stack Rocks On Hikes And What To Do If You See Them

Please don't stack rocks on your next hike. Here's why. - Lonely Planet

I Didn't Know That!: Rock Cairns (U.S. National Park Service)